The invention relates to a sleeve element for axially fixing a bearing and to an exhaust gas turbocharger for an internal combustion engine including such a sleeve element.
Such sleeve elements and turbochargers are known and shown in FIGS. 1 and 2.
FIG. 1 shows a turbocharger 10 for an internal combustion engine, comprising a turbine housing 12, a bearing housing 14 and a compressor housing 16. The turbine housing 12 accommodates a turbine wheel 18 and the compressor housing 16 accommodates a compressor impeller 20, these two components being connected to each other by a shaft 22. The shaft 22 is mounted in the bearing housing 14 by means of radial bearing bushes 24 and 26. In the axial direction along an axis of rotation 28 of the shaft 22, the radial bearing bushes 24 and 26 are located by means of a spacer sleeve 30. The radial bearing bushes 24 and 26 and the spacer sleeve 30 may be rotatable or non-rotatable. The spacer sleeve 30 is installed coaxial with the shaft 22 between the radial bearing bushes 24 and 26.
In FIG. 2, elements identical to those from FIG. 1 are identified by the same reference numbers. In addition to the turbocharger according to FIG. 1, the turbocharger 1′ is provided with a speed sensor 32 which can detect a speed of the shaft 22. The speed sensor 32 may for example be inductive or capacitive, magnetic or optical, or it may detect markings such as flats on the shaft 22, thereby detecting the current speed of the shaft 22 of the turbocharger 10.
A simultaneous use of the speed sensor 32 and a spacer sleeve 30′ for the axial location of the radial bearing bushes 24 and 26 is possible if the spacer sleeve 30′ is designed to be non-rotating, because a speed of a rotatably mounted spacer sleeve does not have to correspond to a speed of the shaft 22. In addition, the speed of the shaft can only be detected if sufficient unimpeded access in the bearing housing 14 of the turbocharger 10′ and a sufficiently large opening in the spacer sleeve 30′ are provided.
Known solutions involve an increased assembly effort for such spacer sleeves 30′ having at least one opening in combination with speed sensors, which increases the costs for turbochargers provided with such an arrangement.
It is the object of the present invention to provide a sleeve element and a turbocharger of the type referred to above in such a way that costs can be reduced.